MLT 126 - Immunology & Serology Exam 4 Actual Questions With 100% Verified Correct Answers.

The CDC recommendations for HIV testing utilize a fourth-generation antigen-antibody test to screen for: a. HIV-1 p24 antigen. b. antibodies to HIV-1 (groups M and O). c. repeated positive HIV-1 and HIV-2 results confirmed with an HIV-1/HIV-2 antibody differentiation test or negative or indeterminate results for HIV-1 or HIV-2 antibody differentiation confirmed with quantitative PCR. d. all the above. - correct answer d. all the above. The most frequent malignancy or opportunistic infection observed in AIDS patients is: a. Pneumocystis jiroveci. b. Kaposi's sarcoma. c. toxoplasmosis. d. non-Hodgkin's lymphoma. - correct answer b. Kaposi's sarcoma. The structures gp41 and gp120 are viral: a. lipids. b. proteins. c. glycoproteins. d. carbohydrates. - correct answer c. glycoproteins. Bruton's disorder is characterized by: a. Inadequate response to Epstein-Barr virus b. T cell defect c. Low levels of antibodies d. Poor humoral response to bacterial polysaccharide antigens - correct answer c. Low levels of antibodies A protein included in the core of the HIV-1 virus is called: a. gp41. b. p24. c. p25. d. Either B or C. - correct answer d. Either B or C. All of the following are examples of Type II hypersensitivity reactions except: a. Farmer's lung and the Arthus reaction. b. immediate transfusion reactions and Hemolytic disease of the newborn (HDN). c. antibody-dependent, cell-mediated cytotoxicity involving NK cells or macrophages expressing Fc receptors. d. antireceptor antibodies such as those expressed in autoimmune thyroid disease. - correct answer a. Farmer's lung and the Arthus reaction. Type I hypersensitivity reactions are characterized by: a. activation of complement. b. antigen cross-links with IgE on mast cells. c. being potentially fatal. d. Both B and C. - correct answer d. Both B and C. The primary action of histamine is: a. Increases vascular permeability. b. Contracts smooth muscle. c. Alters bronchial smooth muscle d. Enhances the effects of serotonin from platelets. - correct answer a. Increases vascular permeability. Anaphylactoid reaction is: a. Cell-mediated b. Antibody-mediated c. Dependent on the host's response to a subsequent exposure of antigen d. Not mediated by antigen-antibody interaction - correct answer d. Not mediated by antigen-antibody interaction The components involved in a positive skin test for tuberculosis (TB) are: a. T lymphocytes and macrophages. b. segmented neutrophils and monocytes. c. B lymphocytes and macrophages. d. IgE antibodies. - correct answer a. T lymphocytes and macrophages. The HIV infectious process begins when the protein on the viral envelope binds to the protein receptor _______ on the surface of a target cell. a. CD8 b. CD4 c. p24 d. p26 - correct answer b. CD4 Typically, patients in the early stages of HIV infection: a. are completely asymptomatic. b. show mild, chronic lymphadenopathy. c. are jaundiced. d. Either A or B. - correct answer d. Either A or B. Which gene is responsible for the coding of reverse transcriptase in the human immunodeficiency virus (HIV)? a. env b. gag c. pol d. tat - correct answer c. pol DiGeorge syndrome is characterized by: a. Inadequate response to Epstein-Barr virus b. T cell defect c. Low levels of antibodies d. Poor humoral response to bacterial polysaccharide antigens - correct answer b. T cell defect In HIV infections, a window period of seronegativity extends from the time of initial infection up to: a. 2 weeks. b. 2 to 6 weeks or longer. c. 6 to 12 weeks or longer. d. 4 to 8 months or longer. - correct answer c. 6 to 12 weeks or longer. Cell-mediated immunity is responsible for: a. contact sensitivity. b. elimination of tumor cells bearing neoantigens. c. rejection of foreign graft tissue. d. all of the above. - correct answer d. all of the above. Immune complex reactions can: a. suppress or augment the immune response. b. inhibit tumor cell destruction. c. be deposited in blood vessel walls, glomerular membranes, and other sites. d. All of the above. - correct answer d. All of the above. Immediate hypersensitivity is: a. Cell-mediated b. Antibody-mediated c. Dependent on the host's response to a subsequent exposure of antigen d. Not mediated by antigen-antibody interaction - correct answer c. Dependent on the host's response to a subsequent exposure of antigen What type of hypersensitivity reaction does Hemolytic Disease of the Fetus and Newborn represent? a. type I b. type II c. type III d. type IV - correct answer b. type II What type of hypersensitivity reaction does the condition, asthma, represent? a. type I b. type II c. type III d. type IV - correct answer a. type I The major structural protein (core) of the human immunodeficiency virus (HIV) type 1 (HIV-1) is composed of: a. gp41. b. p24. c. gp120. d. Both A and C. - correct answer A.GP41 The bands that appear in what is considered a positive Western blot test (WB) for HIV infection are: a. p24 and gp60 b. gp60 and gp160 c. p24 and p31 d. p24 and gp41 - correct answer d. p24 and gp41 In addition to lymphocytes, ___________ and skin cells can be infected by HIV. a. macrophages b. monocytes c. cells in the lymph nodes d. All of the above. - correct answer d. All of the above. Which is the first detectable viral antibody in the blood of a patient with HIV infection? a. p24 b. gp41 c. gp120 d. gp160 - correct answer b. gp41 If an immune dysfunction is suspected in a child, the appropriate workup would be a(n): a. complete blood count, platelet and erythrocyte sedimentation rate b. lymphocyte profile by flow cytometry. c. immunoglobulin electrophoresis. d. All of the above. - correct answer d. All of the above. Anaphylaxis is characterized by all the following statements except: a. it can cause death caused by asphyxiation. b. there is massive release of histamine from mast cells and basophils. c. there was prior sensitization to an allergen. d. it is associated with a significant increase in eosinophils in the circulating blood. - correct answer d. it is associated with a significant increase in eosinophils in the circulating blood. Histamine can: a. lead to constriction of bronchial smooth muscle. b. exert an anticoagulant effect. c. cause decreased capillary permeability. d. enhance opsonization in phagocytosis. - correct answer a. lead to constriction of bronchial smooth muscle. Delayed hypersensitivity is: a. Cell-mediated b. Antibody-mediated c. Dependent on the host's response to a subsequent exposure of antigen d. Not mediated by antigen-antibody interaction - correct answer a. Cell-mediated Immunization or sensitization is: a. Cell-mediated b. Antibody-mediated c. Dependent on the host's response to a subsequent exposure of antigen d. Not mediated by antigen-antibody interaction - correct answer c. Dependent on the host's response to a subsequent exposure of antigen The Arthus reaction is associated with the immune phenomenon of: a. deposition of immune complexes in blood vessels. b. release of histamine from tissue basophils. c. destruction of body tissue by cytotoxic T lymphocytes. d. phagocytosis of IgG-coated erythrocytes. - correct answer a. deposition of immune complexes in blood vessels. In the United States and Western Europe, what percentage of HIV-1 infections are acquired through heterosexual transmission? a. less than 10% b. 25% c. 50% d. more than 90% - correct answer a. less than 10% The human immunodeficiency virus (HIV) attaches itself to receptor sites by means of: a. p24. b. p31. c. gp120. d. gp160. - correct answer c. gp120.